Modular precast concrete unit for a storm water detention or retention system



FIG. 1 is a perspective view of a modular precast concrete unit for a storm water detention or retention system showing my new design;

FIG. 2 is a side view thereof, the opposite and each side view being the same;

FIG. 3 is a top view thereof; and,

FIG. 4 is a bottom view thereof. 

CLAIM The ornamental design for a modular precast concrete unit for a storm water detention or retention system, as shown and described. 